This made it quite effective for the tratment of dental caries and bad breath in Egypt, Greece and Rome, and it was ussed as a wound wash throughout Northern Europe and Arabia.
I seem to recall someone telling me about a song that existed sort of taunting Spaniards (I want to say 1500s or thereabouts?) mocking their bright smiles by saying, approximately, that they know exactly what was swished in their mouths to get those bright teeth.
Don't hold me to this, though.
Also, don't some modern tooth-whitening formulas use uric acid as the active ingredient?